Perl: correct bug introduced by 67481b

The expect_xml function always checked for 'ok', no matter what
the argument was. But this was harmless since the argument always
was 'ok'.
Perl: add -v switch to all commands for debugging
Perl: fix PCap file creation on Windows machines

Windows machines do LF -> CRLF conversion by default. Disable that,
otherwise we get corrupt PCap files.
Fix auto-detection of mingw cross compiler architecture

It was broken on 64 bit linux systems
Eliminate warnings/update cross compiler code for GCC 4.6.4

The MingGW update to GCC 4.6.4 changes a few things in its
header files which caused warnings in our code; eliminate
those warnings.
Fix %z format character so that it works for WIN32 targets
Teach 'make clean' to remove version.c

This cuts the number of ways you can accidentally release code
with false version strings in it.
C: fix usage information for save_to_pcap when piping

Wireshark _can_ capture from stdin or a pipe, but only
if the incoming format is classic Pcap. Pcap-NG doesn't
work. It might work in a future version of Wireshark,
but it doesn't work now (Wireshark 1.10.5).

So: change the examples to nudge people in the right
direction.